Display dial assembly for timepiece

ABSTRACT

The present invention relates to a display dial, such as a day calendar display dial, for a timepiece. The improvement comprises the provision of at least two resilient arms made integral therewith and adapted for easy and positive engagement with a positioning peripheral groove formed on the mounting shaft for the dial.

United States Patent Yasuda et a1.

[451 June 27,1972

DISPLAY DIAL ASSEMBLY FOR TIMEPIECE Tetuya Yasuda; Hidetaka Tutiya;Takeshi Mori, all of Tokyo, Japan Citizen Watch Company Limited, Tokyo,Japan Filed: Dec. 28, 1970 App1.No.: 101,668

Inventors:

Assignee:

Foreign Application Priority Data Dec. 25, 1969 Japan ..44/l04545 June30, 1970 Japan ..45/65l51 Nov. 12, 1970 Japan ..45/111594 US. Cl...58/5, 58/58, 58/152 R Int. Cl. ..G04b 19/24 Field of Search ..58/45,42.5, 43, 125 B, 126 A,

[56] References Cited UNITED STATES PATENTS 2,976,672 3/1961 Ducommun..58/5 X 3,452,535 7/1969 Cabantous et al ..58/4 R PrimaryExaminer-Richard B. Wilkinson Assistant Examiner--Edith C. SimmonsAttorney-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT Thepresent invention relates to a display dial, such as a day calendardisplay dial, for a timepiece.

The improvement comprises the provision of at least two resilient armsmade integral therewith and adapted for easy and positive engagementwith a positioning peripheral groove formed on the mounting shaft forthe dial.

7 Clains, 13 Drawing Figures PATENTEDJUNN m2 SHEET 10F 4 FIG.

FIG. 2

IOc L I lOc IOb DISPLAY DIAL ASSEMBLY FOR TIMEPIECE The presentinvention relates to a display dial, such as a day calendar displaydial, for a timepiece.

It is the main object of the invention to provide a display dial of theabove kind which can be easily attached to and detached from a mountingshaft.

A further object of the invention is to provide a display dial of. theabove kind which is highly easy to manufacture and very cheep in itsmanufacturing cost.

Thesev and further objects, features and advantages of the inventionwillbecome more apparent when reading the followingdetailed description ofseveral preferred embodiments of the inventionby reference to theaccompanying drawings.

In the drawings:

FIG. 1 is aplan view of a first preferred embodiment of the invention, 9

FIG. 2 is a sectional view taken along a section line shown in FIG. 1.

FIG. 3 is'an'axial section of part of a watch to which the pinion-dialassembly is fitted, said dial serving as a day calender display dial forsaid watch.

FIGS. 4 and 5 are similar views to FIGS. 1 and 2, showing, however, apreferred second embodiment of the invention.

FIGS. 6 and7 are similar views to FIGS. 1 and 2, showing, however, apreferred third embodiment of the invention.

FIGS. 8 and 9 are similar views to FIGS. 1 and 2, showing, however, apreferred fourth embodiment of the invention.

2 FIGS. 10 and 11 are similar views to FIGS. 1 and2, showing, however, apreferred fifth embodiment of the invention.

FIGS. 12 and 13 are similar views to FIGS. 1 and 2, show ing, however, apreferred sixth embodiment of the invention.

- Referring now to FIGS. 1 and 2, the first embodiment will be describedhereinbelow in detail.

' In these figures, numeral 10 represents a display dial in itsentirety. This diall fl represents a front surface 10a on which a seriesof radially arranged display marks or symbols such'as names of thecalendar days: Monday, Tuesday and the like, when the dialis used as theday calendar display dial in a timepiece.

The dial 104s formed integrally and rigidly with a plurality ofradially. arranged pinion teeth 10b which have been produced by apressing and punching job, said teeth being positioned at a differentlevelfrom that of the dial proper l0.

Thedial I0 is formedwitha central opening 10f and a pair ofsubstantially concentrically arrangedresilient holder arms lfl'c and10c' whichare positioned substantially in a rotationalsymmetry'with-each-other. These arms and the central opening areformedby the said pressing and punching job. These arms 10 and 10c are formedeach with an inside circular are shaped edge 100' or 10c, respectively,adapted for snuglyengaging with the bottom of a circular groove 3a of amounting shaft 3 the cross-sectional outline of which is shown at 3 isshown in FIGS. 1 and 2 byachain-dottedline, respectively. In practice,however, thisshaft 11 is formed into a tube shaft as most clearly seenfrom FIG. 3. Each. of these resilient arcshaped armsv 10c and 100' isformed on its inside periphery with a recess 10 or 10:, respectively,which serves for dismantling serviceby receiving a manual tool tip.

The dial 10 is formed with a plurality of radially arranged perforations103 after the punch-formation of downwardly ofi'set radial pinion teeth10b.

In FIG. 3, part of a timepiece movement is shown in its axial section.In this movement, the dial. 10 is utilized as day calendar display dial.

Inthis timepiece movement, numeral 12 represents part of a convenu'onallower plate of the movement; 13 shows a second wheel of the gear trainof the movement; 14 represents a cannon pinion. The shaft 11 which hasbeen referred to in the foregoing FIGS. 1 and 2, constitutes practicallythe hollow shaft part of a cannonwheel.

Further in FIG. 3, numeral 16 represents a guard plate which is rigidwith the lower plate 12 and positioned slightly above the cannon wheel15, so as to prevent any stipping disengagement of the wheel 15 from theposition in the timepiece movement.

A day dial drive wheel 17 is rotatably mounted arounda pivot 18 fixedlymounted on the guard plate 16. Numeral 19 represents a conventionaltime-indicator dial of the timepiece, said dial being shown onlypartially andsaid drive wheel 17 being in mesh with said pinion teeth10b.

' Numeral 20 represents a conventional secondhand arbor which is, asconventionally, rotatably mounted in the shaft of center wheel 13. Thetop end of shaft 11 is chamfered at 1 lb.

The members l2, l3, 14, ll; 15, 16, 17, I8, 19 and 20 are ofconventional design and arrangement so that no further description oftheir 1 and and function would-be necessary for better understanding ofthe invention.

The gear-dialassembly 10; 10b accordingto thisinvention can bemanufactured easily on an industrial production scale at a low cost byrelying substantially upon the pressing and stamping job andsubstantially in a single manufacturing step.

When it is intended to fit the aforementioned pinion-dial as, sembly inposition in the timepiece movement as shown in FIG. 3, the assemblyshown in FIGS. 1 and 2 is inserted from upper onto the hollow shaft part11 by utilizing the central opening 10]. At first, the resilient holderarms 10:: and 100' willbeslightly and resiliently expanded outwardly bycontact of the respective arc-shaped inner edge parts IOd'and 10d withthe chamfered shaft end 111:. By moving slippingly the dial l0 along-theoutside surface of shaft part 11, until it comes to the groove 11a, thedial can be snapped into the groove by its resilient arms 10c and 100',thus the dial being firmly positioned at the height of the groove Ila.Therefore, otherwise possible axial shift of the dial [0 relative to thecannon wheel shaft can be positivelyprevented and the dial can beaccurately positioned at the specifically destined position in thetimepiece movement.

- For removal of the dial 10 from position, it is sufilcient to insert atool tip from upper througha central dial opening 190 into one of therecesses-10: or 10c and to exert a slight manual bending moment, so asto expand the resiliently gripping arm or 100', and to slide the dialupward.

The second embodiment is shown in FIGS. 4 and 5. In this embodiment,similar parts are denoted with respective same reference numerals, yeteach being added with 20 for easier comparison andbetter and quickerunderstanding of the invention, regardless, however, of occasional minorconfigurational difference as well as occasional minorfunctional-difference from those of the foregoing first embodiment. v

The display dial 30 has generally a circular disc shape which is formedat its outer periphery with a plurality of or more specifically sevensector-like radial projections 31 and substantially rectangular recesses32 arranged alternatively one after another. Each projection 31 may beara day calendar notification, although not shown.

The dial 30 is formed with a pluralityof radially arranged openings 30 gfor providing enough material for the press-fob. mation of downwardlyoff-set positioned, resilient gripper arms 30c and 300. These arms 30cand 300' are formed and arranged in a perfectly symmetrical way about asection line 5-5.

These resilient gripper arms 30c and 300' are concentrically arrangedwithin the area of a central opening 30f when seen in the plan viewshown in FIG. 4, the respective root portions of these gripper arms areintegral with an offset inner control disc area 33. The dial 30 so farshown and described has been fabricated into its final shape by a singlepressing and punching job.

The gripper arms 30c and 30c are formed with respective tool-tipreception recesses 30c and 30a in the similar way as before, but,dispensed with the shah-gripping arc-shaped edges 30d and 30d. In thiscase, these arms 30c and 300' embrace resiliently the mounting shaft,equally shown by chaindotted line 1 l as before. This shaft 11 isembraced in this case at three points 34, 35 and 36, of which the formertwo points tip ends, while the remaining contact point 36 is selected atthe common root portion of these gripper arms. It should be noted thatin the present embodiment, no pinion teeth such as at b in the foregoingfirst embodiment is provided.

The operation of the present embodiment will be self-explanatory byconsideration of the foregoing structural description thereof incombination with the whole detailed description on the first embodiment.

The third embodiment is shown in FIGS. 6 and 7. In this case, similarparts as before are shown by respective same reference numerals, eachbeing, however, attached with 30.

The display dial in this embodiment is shown at 40 in its entirety.Resilient gripper arms 40c and 400' are arranged in the same level tothat of main body of the dial 40. These arms 40c and 400' are arrangedin a complete circle which is, however, broken at 100. The common rootportion at 101 is made integral with the main body of the dial 40 whichhas a central opening shown at 40f formed substantially into a star.

Gear teeth 40b are formed on the punch-out lower disc portion showngenerally at 102 and having naturally a star shape corresponding that ofthe central opening 405. Projections 40b of this star fonned by thepunched-out lower disc 102 form in combination a plurality of pinionteeth similar to those shown at 10b in FIGS. 1-3.

The display dial 40 fitted and formed with several functional parts sofar shown and described has been manufactured by a single pressing andcut-out job on a press.

The function of the present embodiment is substantially similar to thatof the foregoing first embodiment.

The fourth embodiment is shown in FIGS. 8 and 9. In thisembodimennsimilar constituents are shown with respective same referencesas those of the first embodiment, yet each being added with 40 for clearidentification.

The fourth embodiment of the invention is shown in FIGS. 8 and 9,wherein similar parts with those of the first embodiment are denotedwith respective same reference numerals, yet each being added with 40for clear identification.

The display 50 is formed with a plurality of radially arranged cutouts103-106 and a central opening 50f. A pair of resilient gripper arms 50cand 500' are made integral with the main body of the dial 50, each ofthese arms covering a central angle of about 150 and the free ends ofthese arms are extending a common diameter of the dial 50 which diametercoincides in FIG. 8 with the section line 8-8, the inner extremities ofthese resilient arms having each a slightly concave gripper edges 107and 108 adapted for resiliently contacting with the shaft 11 so as toestablish a tongue-and-groove connection therewith.

Along the inner peripheral edge defining the central opening 50], thereis arranged a plurality of radially arranged recesses 50h, each having asemicircular configuration when seen in FIG. 8, for receiving a pin 107ato be described.

Numeral 109 represents a star wheel made of a plastic resin material andhaving a plurality of radial tooth projections 1090 made integraltherewith. This star wheel 109 is formed with a central opening defineda concentric flange 109d neighboring to a concentric circular groove10%. On the upper surface of the star wheel 109, there is formed aplurality of upwardly projecting pins 109a arranged in a concentriccircle, each of these pins being received in said receiving recesses50h, as was briefly referred to hereinabove, when the star wheel hasbeen assembled together concentrically from below with the display dial50.

Upon mechanically assembling the star wheel with the dial as shown, theupwardly projecting end of each of these pins 1094 is subjected to heatand pressure, so as to provide a flared heat seal connection, as shownat 109a. The star wheel 109 is formed with a center opening 109i forpassing the shaft 1 I with substantial radial idle plays.

As seen from the foregoing, the dial-star wheel assembly provides ahighly rigidly united combination by relatively simple and easymanufacturing process. The easy and positive attachment and detachmentof the dial-star wheel assembly to and from the shaft 11 can be assuredas in the foregoing several embodiments.

The fifth embodiment of the invention is shown in FIGS. 10 and 11 incombination. In this embodiment, similar parts as those of the firstembodiment are denoted with respective same reference numerals, eachbeing, however, added with 50 for clearer identification and comparison.

The display dial, generally shown at 60, is formed with a centralopening for allowing to pass a mounting shaft 1 I as before. The dial isformed with two pairs of resilient and mutually opposed arms, eachhaving substantially a L-shape when seen in their elevational view shownin FIG. 11. Each of these arms 600 is formed with an arc shapedcontacting edges 6011 in close proximity of the free end of the armsubstantially in an inclined manner and adapted for contacting with theshaft groove which is similar to that shown at 114 in the firstembodiment, although not specifically shown.

The shaft 11 is positioned by contact with arc-shaped concave edges 60gdefining substantial part of said center opening 60f. As seen main orworking part of each of the resilient arms 600 is positioned in adownwardly off-set position from the main body of the display dial 60. Aplurality of gear pins 60b are radially provided in an concentric manneraround the center opening 60f, so as to provide practically the functionof a pinion. All these constituents, except pinion pins 60b, have beenformed by a single pressing and cutting-out step on a press, not shown.

The attaching operation of the present dial 60 can be made in thesimilar manner as before. In order to detatch the dial from engagementwith the shafi, a pari of resilient arms 60c when seen in the lateraldirection to the section line 11-11 are forcibly expanded by a pencetteor the like tool.

The sixth embodiment of the invention is shown in FIGS. 12 and 13.

In the present embodiment, similar parts to those used in the firstembodiment are denoted with respective same reference numerals, eachbeing, however, attached with 60 for easier identification andcomparison.

In the present embodiment, three resilient arms 700 are formed andarranged substantially tangentially to a center opening 70f adapted forreception of a shaft denoted again with the same reference numeral 11.There are formed three recesses 70g in close proximity to the tip endsof the resilient arms 70c adapted for reception of a pincette or thelike tool used for the disengaging service.

The operation can be easily understood from the foregoing description,especially from that concerning the foregoing fifih embodiment.

In all the foregoing embodiments, the dial can be rotated with slightfriction around the shaft when the dial is operated The embodiments ofthe invention in which an exclusive property or privilege is claimed aredefined as follows:

1. A display dial, such as day calendar display dial, for a timepiecehaving a central bore for detachable reception of a groove shaft, saiddial being characterized by the provision of at least two resilient armsmade integral with the dial, each of said arm having a concavely curvedportion adapted for pressure contact with the bottom of a peripheralgroove formed on said shaft.

2. A display dial as claimed in claim 1, wherein a pair of saidresilient arms are arranged in a rotary symmetry to each other.

3. A display dial as claimed in claim I, wherein a pair of saidresilient arms are arranged in a symmetry to each other.

4 A display dial as claimed in claim 1, wherein said dial is formed witha concentric and integral pinion teeth made from the same material ofthe dial.

5. A display dial as claimed in claim I, wherein a separate star wheelmade of a plastic material is attached firmly to said dial by fusing aplurality of connection pins.

6. A display dial as claimed in claim 1, wherein said resilient arms arearranged substantially tangentially to said central bore.

7. A display dial as claimed in claim 1, wherein two pairs of saidresilient arms are provided, each pair being arranged in line to eachother and substantially tangentially to said central bore.

1. A display dial, such as day calendar display dial, for a timepiecehaving a central bore for detachable reception of a groove shaft, saiddial being characterized by the provision of at least two resilient armsmade integral with the dial, each of said arm having a concavely curvedportion adapted for pressure contact with the bottom of a peripheralgroove formed on said shaft.
 2. A display dial as claimed in claim 1,wherein a pair of said resilient arms are arranged in a rotary symmetryto each other.
 3. A display dial as claimed in claim 1, wherein a pairof said resilient arms are arranged in a symmetry to each other. 4 Adisplay dial as claimed in claim 1, wherein said dial is formed with aconcentric and integral pinion teeth made from the same material of thedial.
 5. A display dial as claimed in claim 1, wherein a separate starwheel made of a plastic material is attached firmly to said dial byfusing a plurality of connection pins.
 6. A display dial as claimed inclaim 1, wherein said resilient arms are arranged substantiallytangentially to said central bore.
 7. A display dial as claimed in claim1, wherein two pairs of said resilient arms are provided, each pairbeing arranged in line to each other and substantially tangentially tosaid central bore.